// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_BASE_X_X11_FOREIGN_WINDOW_MANAGER_H_
#define UI_BASE_X_X11_FOREIGN_WINDOW_MANAGER_H_

#include <map>
#include <vector>

#include "base/compiler_specific.h"
#include "base/macros.h"
#include "ui/base/ui_base_export.h"
#include "ui/gfx/x/x11_types.h"

// A process wide singleton for selecting events on X windows which were not
// created by Chrome.
namespace base {
template <typename T>
struct DefaultSingletonTraits;
}

namespace ui {

// Manages the events that Chrome has selected on X windows which were not
// created by Chrome. This class allows several clients to select events
// on the same X window.
class UI_BASE_EXPORT XForeignWindowManager {
public:
    static XForeignWindowManager* GetInstance();

    // Requests that events associated with |event_mask| on |xid| be reported to
    // Chrome. Returns an id to use for canceling the request.
    int RequestEvents(XID xid, long event_mask) WARN_UNUSED_RESULT;

    // Cancels the request with |request_id|. Unless there is another request for
    // events on the X window associated with |request_id|, this stops Chrome from
    // getting events for the X window.
    void CancelRequest(int request_id);

    // Called by X11DesktopHandler when |xid| is destroyed.
    void OnWindowDestroyed(XID xid);

private:
    friend struct base::DefaultSingletonTraits<XForeignWindowManager>;

    struct Request {
        Request(int request_id, long entry_event_mask);
        ~Request();

        int request_id;
        long event_mask;
    };

    XForeignWindowManager();
    ~XForeignWindowManager();

    // Updates which events are selected on |xid|.
    void UpdateSelectedEvents(XID xid);

    // The id of the next request.
    int next_request_id_;

    typedef std::vector<Request> RequestVector;
    std::map<XID, RequestVector> request_map_;

    DISALLOW_COPY_AND_ASSIGN(XForeignWindowManager);
};

} // namespace ui

#endif // UI_BASE_X_X11_FOREIGN_WINDOW_MANAGER_H_
